The production of hypochlorite through electrolysis is a fast, reliable and on-site method of producing disinfectants for water treatment. This work presents the modelling of an undivided electrochlorination cell and the experiments carried out on a test cell for model validation. The numerical model made in COMSOL Multiphysics couples the various processes describing the electrochlorination - electrochemistry, chemical reactions, transport of species and two-phase, gas-liquid flow. Thus, establishing a comprehensive model, which can predict the behaviour of the cell. To characterize the dispersed gas bubbles, experiments are carried out using a direct imaging method that enables the capturing of shadow images of bubbles for size, gas volume fraction and velocity determinations. The model is validated against this data and the polarisation curve of the test cell, and its behaviour at varying input parameters is observed through a sensitivity analysis. Additional investigations are conducted for an electrochlorination cell with a smaller cell gap and higher cell voltage, resembling industrial applications.